ExBody2: Advanced Expressive Humanoid Whole-Body Control
This work addresses the problem of expressive whole-body control for humanoid robots, which is incremental as it builds on existing methods with a novel two-step approach.
The paper tackled the challenge of enabling real-world humanoid robots to perform expressive and dynamic whole-body motions while maintaining stability, resulting in a method that produced a policy capable of walking, crouching, and dancing with significant tracking improvement after fine-tuning on small data.
This paper tackles the challenge of enabling real-world humanoid robots to perform expressive and dynamic whole-body motions while maintaining overall stability and robustness. We propose Advanced Expressive Whole-Body Control (Exbody2), a method for producing whole-body tracking controllers that are trained on both human motion capture and simulated data and then transferred to the real world. We introduce a technique for decoupling the velocity tracking of the entire body from tracking body landmarks. We use a teacher policy to produce intermediate data that better conforms to the robot's kinematics and to automatically filter away infeasible whole-body motions. This two-step approach enabled us to produce a student policy that can be deployed on the robot that can walk, crouch, and dance. We also provide insight into the trade-off between versatility and the tracking performance on specific motions. We observed significant improvement of tracking performance after fine-tuning on a small amount of data, at the expense of the others.